Detectando conexões de Internet WiFi, 3G/4G e Conexão de rede em Android utilizando Delphi
Olá.
Hoje precisei garantias que um recurso bastante comum estava disponível para um projeto que estou trabalhando, a internet. Em dispositivos móveis podemos utiliza-la usando conexões de rede WiFi e/ou 3G/4G. Então para que o aplicativo não levante uma exceção já que é necessário verificar os dados no servidor, preciso garantias que ela esteja disponível em uma destas formas.
Já trabalhei em projetos nativos utilizando o Android Studio e este é meu primeiro trabalho profissional usando o Delphi para dispositivos móveis, e no geral tenho gostado, contudo verificar a disponibilidade me deixou meio decepcionado, pois precisei de uma Biblioteca de terceiros (desenvolvida por um MVP da Embarcadeiro que não recordo o nome) pra fazer isso e sinceramente acho que merecia um recurso nativo. Bom pode ser que exista, mas eu não encontrei ninguém falando disto.
Então para resolver o problema utilizei a seguinte biblioteca.
unit NetworkState;
interface
uses
{$IFDEF IOS}
Macapi.ObjectiveC,
Macapi.CoreFoundation,
//Macapi.SystemConfiguration,
Macapi.Dispatch,
iOSApi.CocoaTypes,
iOSApi.Foundation,
Posix.SysSocket;
{$ENDIF}
{$IFDEF ANDROID}
System.SysUtils,
FMX.Helpers.Android,
Androidapi.JNIBridge,
Androidapi.JNI.GraphicsContentViewText,
Androidapi.JNI.JavaTypes,
Androidapi.Helpers;
{$ENDIF}
{$IFDEF IOS}
const
libSystemConfiguration =
'/System/Library/Frameworks/SystemConfiguration.framework/SystemConfiguration';
//libReachability = '/usr/lib/system/libReachability.dylib';
kSCNetworkFlagsConnectionAutomatic = 8;
kSCNetworkFlagsConnectionRequired = 4;
kSCNetworkFlagsInterventionRequired = 16;
kSCNetworkFlagsIsDirect = 131072;
kSCNetworkFlagsIsLocalAddress = 65536;
kSCNetworkFlagsReachable = 2;
kSCNetworkFlagsTransientConnection = 1;
kSCNetworkReachabilityFlagsConnectionAutomatic = 8;
kSCNetworkReachabilityFlagsConnectionOnDemand = 32;
kSCNetworkReachabilityFlagsConnectionOnTraffic = 8;
kSCNetworkReachabilityFlagsConnectionRequired = 4;
kSCNetworkReachabilityFlagsInterventionRequired = 16;
kSCNetworkReachabilityFlagsIsDirect = 131072;
kSCNetworkReachabilityFlagsIsLocalAddress = 65536;
kSCNetworkReachabilityFlagsReachable = 2;
kSCNetworkReachabilityFlagsTransientConnection = 1;
kSCNetworkReachabilityFlagsIsWWAN = $40000;
{$ENDIF}
type
{$IFDEF IOS}
SCNetworkReachabilityFlags = UInt32;
SCNetworkReachabilityRef = ^__SCNetworkReachability;
__SCNetworkReachability = record
end;
SCNetworkReachabilityContext = record
version: CFIndex;
info: Pointer;
retain: function(info: Pointer): Pointer;
release: procedure(info: Pointer);
copyDescription: function(info: Pointer): CFStringRef;
end;
SCNetworkReachabilityContextPtr = ^SCNetworkReachabilityContext;
SCNetworkReachabilityCallback = procedure(target: SCNetworkReachabilityRef;
flags: SCNetworkReachabilityFlags; info: Pointer);
TReachability = class;
Reachability = interface(NSObject)
['{B405394F-57B1-4FF1-83D9-8FBFA38FFD7B}']
function startNotifier: LongBool; cdecl;
procedure stopNotifier; cdecl;
function isReachable: LongBool; cdecl;
function isReachableViaWWAN: LongBool; cdecl;
function isReachableViaWiFi: LongBool; cdecl;
function isConnectionRequired: LongBool; cdecl;
function connectionRequired: LongBool; cdecl;
function isConnectionOnDemand: LongBool; cdecl;
function isInterventionRequired: LongBool; cdecl;
function currentReachabilityStatus: NSInteger; cdecl;
function reachabilityFlags: SCNetworkReachabilityFlags; cdecl;
function currentReachabilityString: NSString; cdecl;
function currentReachabilityFlags: NSString; cdecl;
end;
ReachabilityClass = interface(NSObjectClass)
['{39EC0490-2787-4BB9-95EA-77BB885BFD01}']
function reachabilityWithHostname(hostname: NSString): Pointer; cdecl;
function reachabilityForInternetConnection: Pointer; cdecl;
function reachabilityWithAddress: Pointer; cdecl;
function reachabilityForLocalWiFi: Pointer; cdecl;
end;
TReachability = class(TOCGenericImport)
end;
function SCNetworkReachabilityCreateWithAddress(allocator: CFAllocatorRef;
address: psockaddr): SCNetworkReachabilityRef; cdecl;
external libSystemConfiguration name _PU +
'SCNetworkReachabilityCreateWithAddress';
function SCNetworkReachabilityCreateWithAddressPair(allocator: CFAllocatorRef;
localAddress: psockaddr; remoteAddress: psockaddr): SCNetworkReachabilityRef;
cdecl; external libSystemConfiguration name _PU +
'SCNetworkReachabilityCreateWithAddressPair';
function SCNetworkReachabilityCreateWithName(allocator: CFAllocatorRef;
nodename: PChar): SCNetworkReachabilityRef; cdecl;
external libSystemConfiguration name _PU +
'SCNetworkReachabilityCreateWithName';
function SCNetworkReachabilityGetTypeID: CFTypeID; cdecl;
external libSystemConfiguration name _PU + 'SCNetworkReachabilityGetTypeID';
function SCNetworkReachabilityGetFlags(target: SCNetworkReachabilityRef;
var flags: SCNetworkReachabilityFlags): Boolean; cdecl;
external libSystemConfiguration name _PU + 'SCNetworkReachabilityGetFlags';
function SCNetworkReachabilitySetCallback(target: SCNetworkReachabilityRef;
callout: SCNetworkReachabilityCallback;
var context: SCNetworkReachabilityContext): Boolean; cdecl;
external libSystemConfiguration name _PU + 'SCNetworkReachabilitySetCallback';
function SCNetworkReachabilityScheduleWithRunLoop
(target: SCNetworkReachabilityRef; runLoop: CFRunLoopRef;
runLoopMode: CFStringRef): Boolean; cdecl;
external libSystemConfiguration name _PU +
'SCNetworkReachabilityScheduleWithRunLoop';
function SCNetworkReachabilityUnscheduleFromRunLoop
(target: SCNetworkReachabilityRef; runLoop: CFRunLoopRef;
runLoopMode: CFStringRef): Boolean; cdecl;
external libSystemConfiguration name _PU +
'SCNetworkReachabilityUnscheduleFromRunLoop';
function SCNetworkReachabilitySetDispatchQueue(target: SCNetworkReachabilityRef;
queue: dispatch_queue_t): Boolean; cdecl;
external libSystemConfiguration name _PU +
'SCNetworkReachabilitySetDispatchQueue';
{$IFDEF CPUARM}
function FakeLoader: Reachability; cdecl;
external 'libReachability.a' name 'OBJC_CLASS_$_Reachability';
{$ENDIF}
{$ENDIF}
{$IFDEF ANDROID}
JConnectivityManager = interface;
JNetworkInfo = interface;
JNetworkInfoClass = interface(JObjectClass)
['{E92E86E8-0BDE-4D5F-B44E-3148BD63A14C}']
end;
[JavaSignature('android/net/NetworkInfo')]
JNetworkInfo = interface(JObject)['{6DF61A40-8D17-4E51-8EF2-32CDC81AC372}']
{ Methods }
function isAvailable: Boolean;
cdecl;
function isConnected: Boolean; cdecl;
function isConnectedOrConnecting: Boolean; cdecl;
end;
TJNetworkInfo = class(TJavaGenericImport)
end;
JConnectivityManagerClass = interface(JObjectClass)
['{E03A261F-59A4-4236-8CDF-0068FC6C5FA1}']
{ Property methods }
function _GetTYPE_WIFI: Integer;
cdecl;
function _GetTYPE_WIMAX: Integer; cdecl;
function _GetTYPE_MOBILE: Integer; cdecl;
{ Properties }
property TYPE_WIFI: Integer read _GetTYPE_WIFI;
property TYPE_WIMAX: Integer read _GetTYPE_WIMAX;
property TYPE_MOBILE: Integer read _GetTYPE_MOBILE;
end;
[JavaSignature('android/net/ConnectivityManager')]
JConnectivityManager = interface(JObject)
['{1C4C1873-65AE-4722-8EEF-36BBF423C9C5}']
{ Methods }
function getActiveNetworkInfo: JNetworkInfo;
cdecl;
function getNetworkInfo(networkType: Integer): JNetworkInfo; cdecl;
end;
TJConnectivityManager = class(TJavaGenericImport
JConnectivityManager>)
end;
{$ENDIF}
type
TMobileNetworkStatus = class(TObject)
public
constructor Create;
destructor Destroy; override;
function isConnected: Boolean;
function IsWiFiConnected: Boolean;
function IsMobileConnected: Boolean;
end;
implementation
{$IFDEF ANDROID}
function GetConnectivityManager: JConnectivityManager;
var
ConnectivityServiceNative: JObject;
begin
ConnectivityServiceNative := SharedActivityContext.getSystemService
(TJContext.JavaClass.CONNECTIVITY_SERVICE);
if not Assigned(ConnectivityServiceNative) then
raise Exception.Create('Could not locate Connectivity Service');
Result := TJConnectivityManager.Wrap
((ConnectivityServiceNative as ILocalObject).GetObjectID);
if not Assigned(Result) then
raise Exception.Create('Could not access Connectivity Manager');
end;
{$ENDIF}
{$IFDEF IOS}
function GetInternetReachability: Reachability;
begin
Result := TReachability.Wrap
(TReachability.OCClass.reachabilityForInternetConnection);
end;
{$ENDIF}
constructor TMobileNetworkStatus.Create;
begin
end;
destructor TMobileNetworkStatus.Destroy;
begin
inherited;
end;
function TMobileNetworkStatus.isConnected: Boolean;
{$IFDEF ANDROID}
var
ConnectivityManager: JConnectivityManager;
ActiveNetwork: JNetworkInfo;
{$ENDIF}
begin
{$IFDEF IOS}
Result := GetInternetReachability.isReachable;
{$ENDIF}
{$IFDEF ANDROID}
ConnectivityManager := GetConnectivityManager;
ActiveNetwork := ConnectivityManager.getActiveNetworkInfo;
Result := Assigned(ActiveNetwork) and ActiveNetwork.isConnected;
{$ENDIF}
end;
function TMobileNetworkStatus.IsMobileConnected: Boolean;
{$IFDEF ANDROID}
var
ConnectivityManager: JConnectivityManager;
MobileNetwork: JNetworkInfo;
{$ENDIF}
begin
{$IFDEF IOS}
Result := GetInternetReachability.isReachableViaWWAN;
{$ENDIF}
{$IFDEF ANDROID}
ConnectivityManager := GetConnectivityManager;
MobileNetwork := ConnectivityManager.getNetworkInfo
(TJConnectivityManager.JavaClass.TYPE_MOBILE);
Result := MobileNetwork.isConnected;
{$ENDIF}
end;
function TMobileNetworkStatus.IsWiFiConnected: Boolean;
{$IFDEF ANDROID}
var
ConnectivityManager: JConnectivityManager;
WiFiNetwork: JNetworkInfo;
{$ENDIF}
begin
{$IFDEF IOS}
Result := GetInternetReachability.isReachableViaWiFi;
{$ENDIF}
{$IFDEF ANDROID}
ConnectivityManager := GetConnectivityManager;
WiFiNetwork := ConnectivityManager.getNetworkInfo
(TJConnectivityManager.JavaClass.TYPE_WIFI);
Result := WiFiNetwork.isConnected;
{$ENDIF}
end;
initialization
{$IFDEF IOS}
{$IFDEF CPUARM}
if False then
FakeLoader;
{$ENDIF}
{$ENDIF}
end.
Bom aqui no post ficou bem feio e pouco didático este código todo, mas se um dia precisar disso novamente já sei onde esta e não precisarei ficar pesquisando novamente.
Bom para utilizar esta unit é necessário copia-la pra pasta do seu projeto e em seguida adiciona-la ao mesmo. Conforme figura abaixo:
Feito isto basta utilizar o Use Unit e selecionar NetworkState na parte do projeto onde ira testar a disponibilidade da internet. Especificamente neste projeto foi implementado no FormCreate e evidentemente talvez não seja o melhor evento, mas apenas para demonstração foi usando assim. Veja figura abaixo.:
Nestre caso o método getDadosRest vai ser disparado apenas se for detectado sinal de internet através dos canais WiFi e 3G/4G, caso contrario carregará os dados existentes (se houver) no device.
Apesar de ser uma solução de terceiros funcionou muito bem, nos testes executados e mostrou-se boa alternativa dado a sua simplicidade de uso.
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Até mais.
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